Sir Arnold Kelly can't believe the humidity reading is as high as 67.8%. In the real world, the relative humidity for most of England rarely drops below 70%. England's climate is temperate maritime - heavily influenced by the warm Atlantic gulf stream.
In the mid 60s the Mini Moke failed at its original goal of being a light military vehicle because of a weak engine and poor ground clearance. But the unique look earned it places in a number of TV shows like The Avengers, U.F.O., and The Prisoner, where it was The Village taxi (local service only). Eventually the Mini Moke became an iconic 60s beach buggy and was in production till the 90s.
The thunder sound effect used in this episode is the same thunder SFX used in the opening credits of Patrick McGoohan's series The Prisoner (1967).
The Mini Moke used in this episode is the exact same one used by The Dave Clark 5 in their 1965 film 'Catch us if you can'. (Reg no. BOX 656C)
The Jeep-like vehicle that Emma and Steed drive in this episode is a 1965 Austin Mini Moke.